JP7343786B2 - pneumatic tires - Google Patents

Description

The present invention relates to a pneumatic tire in which a transponder is embedded, and more particularly to a pneumatic tire that makes it possible to improve the durability of the tire while ensuring the communication performance and durability of the transponder.

In pneumatic tires, it has been proposed to embed an RFID tag (transponder) in the tire (for example, see Patent Document 1). If the transponder is placed inside the carcass layer in the tire width direction, radio waves may be blocked by tire constituent members (for example, metal members such as the carcass made of steel or reinforcement) when the transponder communicates, and the communication performance of the transponder may deteriorate. be. Furthermore, when a transponder is embedded in a tire, the tire components are brittle at the start of running in a low-temperature environment, so failures originating from the transponder are likely to occur, and the durability of the tire may deteriorate. Furthermore, depending on the physical properties of the rubber member adjacent to the inside or outside of the transponder in the tire width direction, stress concentration may occur during tire deformation, which may deteriorate the durability of the transponder.

Japanese Unexamined Patent Publication No. 7-137510

An object of the present invention is to provide a pneumatic tire that makes it possible to improve the durability of the tire while ensuring the communication performance and durability of the transponder.

To achieve the above object, the pneumatic tire of the present invention includes a tread portion extending in the circumferential direction of the tire and forming an annular shape, a pair of sidewall portions disposed on both sides of the tread portion, and these sidewall portions. A pneumatic tire comprising a pair of bead portions disposed on the inner side in the tire radial direction, and a carcass layer is mounted between the pair of bead portions, a transponder is embedded outside the carcass layer in the tire width direction, Modulus M50out at 50% deformation at 0°C (0°C) and modulus M50out at 50% deformation at -20°C of the rubber member having the largest storage elastic modulus at 20°C among the rubber members located on the outside in the tire width direction from the transponder. (-20℃) satisfies the relationship of 0.50≦M50out(0℃)/M50out(-20℃)<1.00, and the storage elasticity at 20℃ of the rubber member located inside the transponder in the tire width direction The modulus at 50% deformation at 0°C M50in (0°C) and the modulus at 50% deformation at -20°C M50in (-20°C) of the rubber member with the largest ratio are 0.25≦M50in (0°C)/M50in (- 20° C.)<1.00.

In the present invention, since the transponder is embedded outside the carcass layer in the tire width direction, there is no tire component that blocks radio waves during transponder communication, and transponder communication can be ensured. In addition, the modulus at 50% deformation at 0°C M50out (0°C) and the modulus at 50% deformation at -20°C of the rubber member with the largest storage elastic modulus at 20°C among the rubber members located on the outside in the tire width direction from the transponder. M50out (-20℃), the modulus at 50% deformation at 0℃ of the rubber member with the largest storage elastic modulus at 20℃ among the rubber members located inside the transponder in the tire width direction M50in (0℃) and -20℃ Since the modulus at 50% deformation M50in (-20°C) satisfies the above relational expressions, it is possible to avoid embrittlement of the hard rubber members located inside and outside the transponder in a low-temperature environment, and Stress concentration during tire deformation can be suppressed. This makes it possible to improve the durability of the tire while ensuring the durability of the transponder.

In the pneumatic tire of the present invention, the transponder is covered with a coating layer, and the storage elastic modulus E'c at 0°C (0°C) of the coating layer and the 0°C storage modulus E'c (0°C) of the rubber member adjacent to the outer side of the coating layer in the tire width direction. The storage elastic modulus E'a (0°C) preferably satisfies the relationship 0.15≦E'c (0°C)/E'a (0°C)≦1.30. As a result, the physical properties of the covering layer and the rubber member adjacent to the covering layer become similar, so that it is possible to obtain an effect of dispersing stress during running, and it is possible to effectively improve the durability of the transponder.

The transponder is covered with a covering layer, and the -20°C storage elastic modulus E'c (-20°C) of the covering layer and the -20°C storage elastic modulus E' of the rubber member adjacent to the outer side of the covering layer in the tire width direction. It is preferable that a(-20°C) satisfies the relationship 0.15≦E'c(-20°C)/E'a(-20°C)≦1.30. As a result, the physical properties of the covering layer and the rubber member adjacent to the covering layer become similar, so that it is possible to obtain an effect of dispersing stress during running, and it is possible to effectively improve the durability of the transponder.

Preferably, the transponder is covered with a coating layer, and the storage modulus E'c at -20°C (-20°C) of the coating layer is in the range of 3 MPa to 17 MPa. Thereby, the durability of the transponder can be effectively improved.

The transponder is covered with a covering layer, and the storage elastic modulus at 0°C E'c (0°C) of the covering layer and the storage elastic modulus E'c at -20°C (-20°C) of the covering layer are 0.50≦E. It is preferable to satisfy the relationship 'c(0°C)/E'c(-20°C)≦0.95. As a result, the temperature dependence of the coating layer is reduced, so that the durability of the transponder can be effectively improved in a low-temperature environment.

Preferably, the transponder is covered with a covering layer, and the relative dielectric constant of the covering layer is 7 or less. Thereby, the transponder is protected by the coating layer, and the durability of the transponder can be improved, and the radio wave transparency of the transponder can be ensured, so that the communication performance of the transponder can be effectively improved.

The transponder is covered with a cover layer, which preferably consists of a rubber or elastomer and a white filler of 20 phr or more. As a result, the dielectric constant of the coating layer can be made relatively lower than that in the case of containing carbon, and the communication performance of the transponder can be effectively improved.

Preferably, the white filler contains 20 phr to 55 phr calcium carbonate. Thereby, the dielectric constant of the covering layer can be made relatively low, and the communication performance of the transponder can be effectively improved.

Preferably, the center of the transponder is spaced apart from the splice portion of the tire component by 10 mm or more in the tire circumferential direction. Thereby, the durability of the tire can be effectively improved.

It is preferable that the transponder is disposed between a position 15 mm outward in the tire radial direction from the upper end of the bead core of the bead portion and the tire maximum width position. As a result, the transponder is placed in a region where the stress amplitude during driving is small, so the durability of the transponder can be effectively improved, and furthermore, the durability of the tire is not reduced.

It is preferable that the distance between the cross-sectional center of the transponder and the outer surface of the tire is 2 mm or more. Thereby, the durability of the tire can be effectively improved, and the trauma resistance of the tire can also be improved.

The transponder is covered with a covering layer, the thickness of which is preferably between 0.5 mm and 3.0 mm. Thereby, the communication performance of the transponder can be effectively improved without creating irregularities on the outer surface of the tire.

The transponder includes an IC board that stores data and an antenna that transmits and receives data, and the antenna preferably has a spiral shape. Thereby, it is possible to follow the deformation of the tire during driving, and the durability of the transponder can be improved.

In the present invention, the storage modulus E' is measured using a viscoelastic spectrometer in accordance with JIS-K6394, at each specified temperature, frequency 10Hz, initial strain 10%, dynamic strain ±2 % condition. In addition, the modulus at 50% deformation is measured at 50% elongation using a No. 3 dumbbell-shaped test piece at specified temperatures and tensile speeds of 500 mm/min in accordance with JIS-K6251. is the tensile stress of However, if a No. 3 dumbbell-shaped test piece cannot be collected from the tire, a test piece with a different shape may be used.

1 is a meridian half-sectional view showing a pneumatic tire according to an embodiment of the present invention. 2 is a meridian cross-sectional view schematically showing the pneumatic tire of FIG. 1. FIG. FIG. 2 is an equatorial cross-sectional view schematically showing the pneumatic tire of FIG. 1. FIG. FIG. 2 is an enlarged cross-sectional view of a transponder embedded in the pneumatic tire of FIG. 1. FIG. (a) and (b) are perspective views showing a transponder that can be embedded in a pneumatic tire according to the present invention. FIG. 3 is an explanatory diagram showing the tire radial direction position of a transponder in a test tire.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. 1 to 4 show pneumatic tires according to embodiments of the present invention.

As shown in FIG. 1, the pneumatic tire of the present embodiment includes a tread portion 1 extending in the tire circumferential direction and forming an annular shape, a pair of sidewall portions 2 disposed on both sides of the tread portion 1, and a pair of sidewall portions 2 disposed on both sides of the tread portion 1. A pair of bead portions 3 are provided on the inner side of the sidewall portion 2 in the tire radial direction.

At least one carcass layer 4 (one layer in FIG. 1) formed by arranging a plurality of carcass cords in the radial direction is mounted between the pair of bead portions 3. The carcass layer 4 is coated with rubber. As the carcass cord constituting the carcass layer 4, organic fiber cords such as nylon and polyester are preferably used. An annular bead core 5 is embedded in each bead portion 3, and a bead filler 6 made of a rubber composition having a triangular cross section is arranged on the outer periphery of the bead core 5.

On the other hand, a plurality of belt layers 7 (two layers in FIG. 1) are embedded in the tire outer circumferential side of the carcass layer 4 in the tread portion 1. The belt layer 7 includes a plurality of reinforcing cords that are inclined with respect to the tire circumferential direction, and the reinforcing cords are arranged so as to cross each other between layers. In the belt layer 7, the inclination angle of the reinforcing cords with respect to the tire circumferential direction is set, for example, in the range of 10° to 40°. As the reinforcing cord for the belt layer 7, a steel cord is preferably used.

On the outer peripheral side of the tire of the belt layer 7, there is at least one layer (two layers in FIG. 1) of reinforcing cords arranged at an angle of, for example, 5° or less with respect to the tire circumferential direction, for the purpose of improving high-speed durability. A belt cover layer 8 is arranged. In FIG. 1, the belt cover layer 8 located on the inside in the tire radial direction constitutes a full cover covering the entire width of the belt layer 7, and the belt cover layer 8 located on the outside in the tire radial direction covers only the end portion of the belt layer 7. It constitutes an edge cover layer. As the reinforcing cord for the belt cover layer 8, organic fiber cords such as nylon and aramid are preferably used.

In the above pneumatic tire, both ends 4e of the carcass layer 4 are folded back around each bead core 5 from the inside of the tire to the outside, and are arranged so as to wrap around the bead core 5 and the bead filler 6. The carcass layer 4 includes a main body portion 4A that extends from the tread portion 1 through each sidewall portion 2 to each bead portion 3, and a main body portion 4A that is a portion extending from the tread portion 1 to each bead portion 3 via each sidewall portion 2, and a body portion 4A that is wound up around a bead core 5 at each bead portion 3 and extends to each sidewall portion 2 side. It includes a winding portion 4B which is a portion extending toward the front.

Further, an inner liner layer 9 is arranged along the carcass layer 4 on the inner surface of the tire. A cap tread rubber layer 11 is arranged on the tread part 1, a sidewall rubber layer 12 is arranged on the sidewall part 2, and a rim cushion rubber layer 13 is arranged on the bead part 3.

Further, in the pneumatic tire described above, a transponder 20 is embedded in a portion outside the carcass layer 4 in the tire width direction. The transponder 20 extends along the tire circumferential direction. The transponder 20 may be arranged so as to be inclined in the range of −10° to 10° with respect to the tire circumferential direction.

As the transponder 20, for example, an RFID (Radio Frequency Identification) tag can be used. As shown in FIGS. 5A and 5B, the transponder 20 includes an IC board 21 that stores data and an antenna 22 that transmits and receives data in a non-contact manner. By using such a transponder 20, information regarding tires can be written or read in a timely manner, and tires can be managed efficiently. Note that RFID is an automatic recognition technology that is composed of a reader/writer having an antenna and a controller, and an ID tag having an IC board and an antenna, and is capable of communicating data wirelessly.

The overall shape of the transponder 20 is not particularly limited, and for example, a columnar or plate-like shape can be used as shown in FIGS. 5(a) and 5(b). In particular, it is preferable to use the columnar transponder 20 shown in FIG. 5(a) because it can follow the deformation of the tire in each direction. In this case, the antenna 22 of the transponder 20 protrudes from each end of the IC board 21 and has a spiral shape. Thereby, it is possible to follow the deformation of the tire during driving, and the durability of the transponder 20 can be improved. Furthermore, by appropriately changing the length of the antenna 22, communication performance can be ensured.

Furthermore, in the pneumatic tire, the storage elastic modulus E'out (20 ℃) corresponds to the rim cushion rubber layer 13. On the other hand, among the rubber members located inside the transponder 20 in the tire width direction (in FIG. 1, the coat rubber of the carcass layer 4, the bead filler 6, and the inner liner layer 9), the storage elastic modulus E'in (20°C) is The largest rubber member (hereinafter also referred to as an internal member) corresponds to the bead filler 6. Note that the coating layer 23 covering the transponder 20, which will be described later, is not included as the rubber member (external material or internal material) having the largest storage modulus at 20°C.

In the region inside the tire radial direction from the apex of the bead filler 6, the storage elastic modulus E'out (20°C) at 20°C of the outer material can be set in the range of 8 MPa to 12 MPa, and the storage elastic modulus E'out (20°C) of the inner material at 20°C The storage elastic modulus E'in (20° C.) of can be set in the range of 9 MPa to 120 MPa. In addition, in the flex zone outside the apex of the bead filler 6 in the tire radial direction, the storage elastic modulus E'out (20°C) of the external material at 20°C can be set in the range of 3 MPa to 5 MPa, and the internal The 20°C storage elastic modulus E'in (20°C) of the material can be set in the range of 5 MPa to 7 MPa.

Here, the modulus M50out (0°C) at 50% deformation at 0°C and the modulus M50out (20°C) at 50% deformation at -20°C of the external material are 0.50≦M50out (0°C)/M50out (- 20℃) < 1.00, and the modulus M50in (0℃) at 50% deformation at 0℃ and the modulus M50in (-20℃) at 50% deformation at -20℃ of the above internal material are 0.25≦ The relationship M50in (0°C)/M50in (-20°C) < 1.00 is satisfied. In particular, it is preferable to satisfy the following relationships: 0.7≦M50out (0°C)/M50out (-20°C)≦0.9 and 0.5≦M50in (0°C)/M50in (-20°C)≦0.9 .

At that time, the modulus M50out (0°C) at 50% deformation at 0°C of the external material is set in the range of 1.5 MPa to 5 MPa, and the modulus M50in (0°C) at 50% deformation at 0°C of the internal material is set to the range of 1.5 MPa to 5 MPa. It is recommended to set it between 2.5 MPa and 15 MPa.

In addition, although the embodiment of FIG. 1 showed the example where the transponder 20 was arrange|positioned between the rolled-up part 4B of the carcass layer 4 and the rim cushion rubber layer 13, it is not limited to this. Alternatively, the transponder 20 can be placed between the main body 4A of the carcass layer 4 and the sidewall rubber layer 12. The external material and internal material vary depending on the placement location of the transponder 20, but in any case, the modulus of the external material at 50% deformation at 0°C M50out (0°C) and at 50% deformation at -20°C The modulus M50out (-20℃), the modulus M50in (0℃) at 50% deformation at 0℃ and the modulus M50in (-20℃) at 50% deformation at -20℃ of the internal material satisfy the above relational expression. It is set as follows.

In the above-mentioned pneumatic tire, the transponder 20 is buried outside the carcass layer 4 in the tire width direction, so there is no tire component that blocks radio waves when the transponder 20 communicates, and the communication performance of the transponder 20 can be ensured. can. In addition, the modulus M50out at 50% deformation at 0°C and the 50% deformation at -20°C of the rubber member having the largest storage elastic modulus at 20°C among the rubber members located outside the transponder 20 in the tire width direction. The modulus M50out (-20°C) satisfies the relationship 0.50≦M50out (0°C)/M50out (-20°C) < 1.00, and the 20°C The modulus M50in at 50% deformation at 0°C (0°C) and the modulus M50in at 50% deformation at -20°C (-20°C) of the rubber member with the largest storage modulus are 0.25≦M50in (0°C)/M50in (-20°C) < 1.00, it is possible to avoid embrittlement of the hard rubber members located inside and outside the transponder 20 in a low-temperature environment, and to reduce stress concentration during tire deformation. Can be suppressed. Thereby, the durability of the tire can be improved while ensuring the durability of the transponder 20.

Here, if the value of M50out (0°C)/M50out (-20°C) or M50in (0°C)/M50in (-20°C) is smaller than the lower limit value, the rubber member located inside or outside of the transponder 20 Stress concentration occurs during deformation, which deteriorates the durability of the transponder 20 in a low-temperature environment. Conversely, if the value of M50out (0℃)/M50out (-20℃) or M50in (0℃)/M50in (-20℃) is larger than the upper limit, the modulus at 50% deformation at 0℃ and -20℃ The rate of change from the modulus at 50% deformation is small, and these rubber members become brittle, leading to a decrease in tire durability.

Note that it is preferable that the temperature dependence of the physical properties of the external material is small, since this increases the protection of the transponder 20 against tire deformation during driving. Therefore, the relationship M50out (0°C)/M50out (-20°C) > M50in (0°C)/M50in (-20°C) is satisfied, and furthermore, 1.1 x M50in (0°C)/M50in (-20°C )≦M50out (0°C)/M50out (-20°C)≦1.3×M50in (0°C)/M50in (-20°C).

In the pneumatic tire described above, the transponder 20 is arranged at a position P1 located 15 mm outward in the tire radial direction from the upper end 5e (tire radially outer end) of the bead core 5, and at a position where the tire has the maximum width. It is preferable to place it between P2 and P2. That is, the transponder 20 is preferably placed in the area S1 shown in FIG. When the transponder 20 is placed in the area S1, the transponder 20 is located in an area where the stress amplitude during driving is small, so the durability of the transponder 20 can be effectively improved, and furthermore, the durability of the tire can be reduced. I have nothing to do. Here, if the transponder 20 is disposed inside the position P1 in the tire radial direction, the communication performance of the transponder 20 tends to deteriorate because it comes close to a metal member such as the bead core 5. On the other hand, if the transponder 20 is placed outside the position P2 in the tire radial direction, the transponder 20 will be located in an area where the stress amplitude during driving is large, resulting in damage to the transponder 20 itself or interfacial peeling around the transponder 20. This is not preferable because it tends to occur.

As shown in FIG. 3, there are a plurality of splice parts on the circumference of the tire, which are formed by overlapping the ends of tire constituent members. FIG. 3 shows the position Q of each splice portion in the tire circumferential direction. The center of the transponder 20 is preferably spaced apart from the splice portion of the tire component by 10 mm or more in the tire circumferential direction. That is, the transponder 20 is preferably placed in the area S2 shown in FIG. 3. Specifically, it is preferable that the IC board 21 constituting the transponder 20 is spaced apart from the position Q by 10 mm or more in the tire circumferential direction. Furthermore, it is more preferable that the entire transponder 20 including the antenna 22 is spaced apart from the position Q by 10 mm or more in the tire circumferential direction. Most preferably, they are spaced apart by 10 mm or more. Further, as the tire component disposed apart from the transponder 20, it is preferable that the sidewall rubber layer 12, the rim cushion rubber layer 13, or the carcass layer 4 are disposed adjacent to the transponder 20. By arranging the transponder 20 at a distance from the splice portion of the tire component in this way, the durability of the tire can be effectively improved.

Although the embodiment shown in FIG. 3 shows an example in which the positions Q of the splice portions of each tire component in the tire circumferential direction are arranged at equal intervals, the present invention is not limited thereto. The position Q in the tire circumferential direction can be set at any position, and in any case, the transponder 20 is arranged so as to be spaced apart from the splice portion of each tire component by 10 mm or more in the tire circumferential direction.

As shown in FIG. 4, the distance d between the center of the cross section of the transponder 20 and the outer surface of the tire is preferably 2 mm or more. By separating the transponder 20 and the outer surface of the tire in this manner, the durability of the tire can be effectively improved, and the trauma resistance of the tire can also be improved.

Further, the transponder 20 is preferably covered with a covering layer 23. This coating layer 23 covers the entire transponder 20 so as to sandwich both the front and back sides of the transponder 20 . The covering layer 23 may be made of rubber having the same physical properties as the rubber constituting the sidewall rubber layer 12 or the rim cushion rubber layer 13, or may be made of rubber having different physical properties. Since the transponder 20 is protected by the covering layer 23, the durability of the transponder 20 can be improved.

The covering layer 23 covering the transponder 20 will be described in detail below. Regarding the physical properties of the coating layer 23, the storage modulus E'c (-20°C) of the coating layer 23 at -20°C is preferably in the range of 3 MPa to 17 MPa. By setting the physical properties of the coating layer 23 in this way, the durability of the transponder 20 can be effectively improved.

The 0°C storage elastic modulus E'c (0°C) of the coating layer 23 and the -20°C storage elastic modulus E'c (-20°C) of the covering layer 23 are 0.50≦E'c(0 ℃)/E'c(-20℃)≦0.95. By setting the physical properties of the covering layer 23 in this way, the temperature dependence of the covering layer 23 is reduced (the covering layer 23 is less likely to generate heat), which effectively improves the durability of the transponder 20 in a low-temperature environment. can do. Here, if the value of E'c (0°C)/E'c (-20°C) is smaller than the lower limit, the rate of change between the storage modulus at 0°C and -20°C is large; The rigidity of the covering layer 23 on the high temperature side is reduced, and the protective effect of the covering layer 23 on the transponder 20 is reduced. On the other hand, if the value of E'c (0°C)/E'c (-20°C) is larger than the upper limit, the rate of change between the storage modulus at 0°C and -20°C is excessively small; When the tire generates heat, the rigidity of the covering layer 23 becomes higher than the surrounding rubber members, making the covering layer 23 more likely to break, and the protective effect of the covering layer 23 on the transponder 20 is reduced.

In addition, the storage elastic modulus E'c (0°C) at 0°C of the coating layer 23 and the storage elasticity at 0°C of the rubber member (rim cushion rubber layer 13 in FIG. 4) adjacent to the outer side of the covering layer 23 in the tire width direction The ratio E'a (0°C) preferably satisfies the relationship 0.15≦E'c (0°C)/E'a (0°C)≦1.30. By setting the physical properties of the covering layer 23 and the rubber member adjacent to the covering layer 23 in this way, the physical properties of the two become similar, so it is possible to obtain a stress dispersion effect during running, and the transponder 2 can effectively improve the durability of

-20°C storage elastic modulus E'c (-20°C) of the covering layer 23 and -20°C storage elastic modulus E'a (-20°C) of the rubber member adjacent to the outer side of the covering layer 23 in the tire width direction preferably satisfies the relationship 0.15≦E'c (-20°C)/E'a (-20°C)≦1.30. By setting the physical properties of the covering layer 23 and the rubber member adjacent to the covering layer 23 in this way, the physical properties of the two become similar, so it is possible to obtain a stress dispersion effect during running, and the transponder 2 can effectively improve the durability of

As for the composition of the covering layer 23, it is preferable that the covering layer 23 consists of rubber or elastomer and a white filler of 20 phr or more. By configuring the covering layer 23 in this way, the dielectric constant of the covering layer 23 can be made relatively low compared to the case where carbon is contained, and the communication performance of the transponder 20 can be effectively improved. . In this specification, "phr" means parts by weight per 100 parts by weight of the rubber component (elastomer).

The white filler constituting this coating layer 23 preferably contains 20 phr to 55 phr of calcium carbonate. Thereby, the dielectric constant of the covering layer 23 can be made relatively low, and the communication performance of the transponder 20 can be effectively improved. However, if the white filler contains too much calcium carbonate, it becomes brittle and the strength of the coating layer 23 decreases, which is not preferable. In addition to calcium carbonate, the coating layer 23 can optionally contain 20 phr or less of silica (white filler) and 5 phr or less of carbon black. When a small amount of silica or carbon black is used in combination, the strength of the coating layer 23 can be ensured and the dielectric constant can be lowered.

Further, the dielectric constant of the coating layer 23 is preferably 7 or less, more preferably 2 to 5. By appropriately setting the dielectric constant of the coating layer 23 in this manner, radio wave transparency when the transponder 20 emits radio waves can be ensured, and the communication performance of the transponder 20 can be effectively improved. The rubber constituting the covering layer 23 has a relative dielectric constant of 860 MHz to 960 MHz at room temperature. Here, the normal temperature is 23±2° C. and 60%±5% RH in accordance with the standard condition of the JIS standard. After the rubber is treated at 23° C. and 60% RH for 24 hours, the dielectric constant is measured by a capacitance method. The above-mentioned range of 860 MHz to 960 MHz corresponds to the current assigned frequency of RFID in the UHF band, but if the above assigned frequency is changed, the relative permittivity of the assigned frequency range may be defined as described above.

The thickness t of the coating layer 23 is preferably 0.5 mm to 3.0 mm, more preferably 1.0 mm to 2.5 mm. Here, the thickness t of the coating layer 23 is the rubber thickness at a position including the transponder 20, and for example, as shown in FIG. The rubber thickness is the sum of the thickness t1 and the thickness t2. By appropriately setting the thickness t of the coating layer 23 in this way, it is possible to effectively improve the communication performance of the transponder 20 without creating irregularities on the outer surface of the tire. Here, if the thickness t of the covering layer 23 is thinner than 0.5 mm, the effect of improving the communication performance of the transponder 20 cannot be obtained, and conversely, if the thickness t of the covering layer 23 exceeds 3.0 mm, Unevenness occurs on the outer surface of the tire, which is unfavorable in terms of appearance. Note that the cross-sectional shape of the coating layer 23 is not particularly limited, and may be, for example, triangular, rectangular, trapezoidal, or spindle-shaped. The covering layer 23 in FIG. 4 has a substantially spindle-shaped cross-sectional shape.

In the embodiment described above, an example was shown in which the end 4e of the rolled up part 4B of the carcass layer 4 was arranged near the upper end 6e of the bead filler 6, but the invention is not limited to this, and the rolled up part 4B of the carcass layer 4 The terminal 4e can be placed at any height.

The tire size is 265/40ZR20, and it has a tread part extending in the tire circumferential direction and forming an annular shape, a pair of sidewall parts arranged on both sides of the tread part, and a pair of sidewall parts arranged on the inside of these sidewall parts in the tire radial direction. In a pneumatic tire comprising a pair of bead parts and a carcass layer mounted between the pair of bead parts, a transponder is embedded, and the position of the transponder in the tire width direction, the position of the transponder in the tire radial direction, M50 out (0 °C)/M50out (-20°C), M50in (0°C)/M50in (-20°C), presence or absence of a covering layer, dielectric constant of the covering layer, thickness of the covering layer, storage modulus of the covering layer E'c (0°C), storage modulus of coating layer E'c (-20°C), E'c (0°C)/E'a (0°C), E'c (-20°C)/E'a (- Tires of Comparative Examples 1 to 4 and Examples 1 to 14 were manufactured with E'c (0°C)/E'c (-20°C) set as shown in Tables 1 and 2.

In Comparative Examples 1 to 4 and Examples 1 to 14, a columnar transponder was used, the distance in the tire circumferential direction from the center of the transponder to the splice part of the tire component was set to 10 mm, and the distance from the cross-sectional center of the transponder to the outside of the tire was set to 10 mm. The distance to the surface was set to 2 mm or more.

In Tables 1 and 2, when the position of the transponder in the tire width direction is "inside", it means that the transponder is placed on the inside of the carcass layer in the tire width direction; '' means that the transponder is disposed on the outside of the carcass layer in the tire width direction. Furthermore, in Tables 1 and 2, the positions of the transponders in the tire radial direction correspond to the positions A to E shown in FIG. 6, respectively.

In Comparative Examples 2 to 4 and Examples 1 to 14, the outer material is a rim cushion rubber layer, and the inner material is a bead filler. That is, in Tables 1 and 2, "M50out(0℃)/M50out(-20℃)" is the ratio of the modulus at 50% deformation in the rim cushion rubber layer, and "M50in(0℃)/M50in(-20℃)" is the ratio of the modulus at 50% deformation in the rim cushion rubber layer. 20°C) is the ratio of the modulus at 50% deformation of the bead filler, which is the internal material. In addition, "E'c (0°C) / E'a (0°C)" and "E'c (-20°C) / E'a (-20°C)" are adjacent to the outer side of the coating layer in the tire width direction. It is the ratio of the storage elastic modulus of the covering layer to the storage elastic modulus of the rim cushion rubber layer, which is a rubber member that acts as a rubber member. "E'c (0°C)/E'c (-20°C)" is the ratio of storage modulus in the coating layer. For Comparative Example 1, for convenience, the physical properties of the rim cushion rubber layer are shown as the physical properties of the external material, and the physical properties of the bead filler are shown as the physical properties of the internal material.

These test tires were subjected to tire evaluation (durability) and transponder evaluation (communication performance and durability) using the following test methods, and the results are also shown in Tables 1 and 2.

Durability (tires and transponders):
Each test tire was assembled onto a wheel with a standard rim, and a running test was conducted on a drum testing machine at a temperature of -20°C, an air pressure of 120 kPa, 102% of the maximum load, and a running speed of 81 km, and the tire failed. The distance traveled was measured. The evaluation results were expressed as an index with Comparative Example 2 as 100. The larger the index value, the better the tire durability. In addition, we checked whether transponder communication was possible and whether there was any damage for each test tire after the end of the run, and cases where communication was possible and there was no damage were indicated with an "◎ (excellent)", and cases where communication was possible but there was damage were indicated. Cases are indicated by "○ (good)", and cases where communication is not possible are indicated by "× (impossible)".

Communication (transponder):
For each test tire, a reader/writer was used to communicate with the transponder. Specifically, the maximum communication distance was measured using a reader/writer with an output of 250 mW and a carrier frequency of 860 MHz to 960 MHz. The evaluation results were expressed as an index with Comparative Example 2 as 100. The larger the index value, the better the communication performance.

As can be seen from Tables 1 and 2, the pneumatic tires of Examples 1 to 14 had improved tire durability and transponder communication and durability in a well-balanced manner compared to Comparative Example 2.

On the other hand, in Comparative Example 1, since the transponder was arranged inside the carcass layer in the tire width direction, the communication performance of the transponder deteriorated. In Comparative Examples 1 and 3, the values of M50out (0°C)/M50out (-20°C) or M50in (0°C)/M50in (-20°C) were set lower than the range specified by the present invention, The effect of improving the durability of the transponder could not be obtained. In Comparative Example 4, the values of M50out (0°C)/M50out (-20°C) or M50in (0°C)/M50in (-20°C) were set higher than the range specified by the present invention, so the tire Durability deteriorated.

1 Tread portion 2 Sidewall portion 3 Bead portion 4 Carcass layer 5 Bead core 6 Bead filler 7 Belt layer 12 Sidewall rubber layer 13 Rim cushion rubber layer 20 Transponder 23 Covering layer CL Tire center line

Claims (13)

A tread portion extending in the circumferential direction of the tire and forming an annular shape, a pair of sidewall portions disposed on both sides of the tread portion, and a pair of bead portions disposed inside the sidewall portions in the tire radial direction. A pneumatic tire comprising: a carcass layer mounted between the pair of bead portions;
A transponder is embedded outside the carcass layer in the tire width direction, and the modulus M50out ( The modulus M50out (-20°C) at 50% deformation at 0°C) and -20°C satisfies the relationship 0.50≦M50out (0°C)/M50out (-20°C) < 1.00, and the tire width is determined by the transponder. Modulus at 50% deformation at 0°C M50in (0°C) and modulus at 50% deformation at -20°C M50in (-20°C) of the rubber member with the largest storage elastic modulus at 20°C among the rubber members located on the inside in the direction A pneumatic tire, characterized in that satisfies the relationship: 0.25≦M50in (0°C)/M50in (-20°C) < 1.00. The transponder is covered with a coating layer, and the storage elastic modulus at 0° C. E'c (0° C.) of the coating layer, and the storage elastic modulus E' at 0° C. of the rubber member adjacent to the outer side of the coating layer in the tire width direction. The pneumatic tire according to claim 1, wherein a (0°C) satisfies the relationship of 0.15≦E'c (0°C)/E'a (0°C)≦1.30. The transponder is covered with a covering layer, and the -20°C storage elastic modulus E'c (-20°C) of the covering layer, and the -20°C storage elasticity of the rubber member adjacent to the outer side of the covering layer in the tire width direction. Claim 1 or 2, characterized in that the ratio E'a (-20°C) satisfies the relationship 0.15≦E'c (-20°C)/E'a (-20°C)≦1.30. Pneumatic tires listed in. Any one of claims 1 to 3, wherein the transponder is covered with a covering layer, and the storage modulus E'c (-20° C.) of the covering layer is in the range of 3 MPa to 17 MPa. Pneumatic tires listed. The transponder is covered with a coating layer, and the storage modulus of elasticity at 0°C E'c (0°C) of the coating layer and the storage modulus of elasticity E'c of the coating layer at -20°C (-20°C) are 0. The pneumatic tire according to any one of claims 1 to 4, which satisfies the relationship: 50≦E'c (0°C)/E'c (-20°C)≦0.95. The pneumatic tire according to any one of claims 1 to 5, wherein the transponder is covered with a coating layer, and the coating layer has a dielectric constant of 7 or less. The pneumatic tire according to any one of claims 1 to 6, wherein the transponder is covered with a coating layer, and the coating layer is made of rubber or elastomer and a white filler of 20 phr or more. The pneumatic tire according to claim 7, wherein the white filler contains 20 phr to 55 phr of calcium carbonate. The pneumatic tire according to any one of claims 1 to 8, wherein the center of the transponder is disposed at a distance of 10 mm or more in the tire circumferential direction from a splice portion of a tire component. The pneumatic pump according to any one of claims 1 to 9, wherein the transponder is arranged between a position 15 mm outward in the tire radial direction from the upper end of the bead core of the bead portion and a tire maximum width position. tire. The pneumatic tire according to any one of claims 1 to 10, characterized in that the distance between the cross-sectional center of the transponder and the outer surface of the tire is 2 mm or more. The pneumatic tire according to any one of claims 1 to 11, characterized in that the transponder is covered with a coating layer, and the thickness of the coating layer is 0.5 mm to 3.0 mm. The pneumatic tire according to any one of claims 1 to 12, wherein the transponder has an IC board for storing data and an antenna for transmitting and receiving data, and the antenna has a spiral shape.

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